View Full Version : Ronar Rings

John D Gerndt
12-Feb-2005, 16:46
I thought there was a consensus about the spacer rings on Ronar lenses. I thought that removing the rings tended to better the lens for focus at infinity. I cannot find mention of this. Am I dreaming?


Arne Croell
13-Feb-2005, 07:16
I am not aware of any spacer rings for Apo-Ronars. Mine (bought in shutter) certainly don't have any. The only rings that I know of were the ones that Docter offered for their Apo-Germinars the last years before the bankruptcy. Those rings need to be _installed_ for the infinity optimization.

Jason Greenberg Motamedi
13-Feb-2005, 08:30

I think you are confusing the discussion around the Graphic-Kowa/Kvytar/Computar lenses with the Apo-Ronar. The Kowa lenses came with a spacing ring which could be removed.

13-Feb-2005, 15:13
My 480/9 came in a Sinar DB mount (the lens is actually marked 480/11 because of the mount, I think) with a 0.3mm thick spacer under the front element. In comparing shots taken with and without the spacer, I couldn't really tell any difference, so for now I've left it out.

CP Goerz
13-Feb-2005, 15:16
Generally speaking not all lenses of the same design need spacer rings. Slight variations in focal length of the actual glass (which always happens) needs to be adjusted for in the spacing of the cells. If the glass is within the tolerance range for a given barrel/shutter mount then no spacers are needed. If the glass does need more correction then the spacers will be used to adjust for it. Just about every manufacturer has used spacers....except Goerz who made perfect lenses all the time :-)

Early meniscus lenses came with a pair of 1/4" rims that were used as spacers that gave a better correction for the center of the image at the expense of the image circle size.

CP Goerz

John D Gerndt
13-Feb-2005, 19:37
Thanks all for the informed replies. I will just leave the spacer in, as built.